1. Field of the Invention
The present invention relates to a module battery and a method of manufacturing the module battery.
2. Description of Related Art
Module batteries of sodium-sulfur batteries include a large number of cells connected in series and in parallel. For example, Patent Literature 1 discloses that two or more cells (electric cells 2) connected in series form a string, two or more strings connected in parallel via a parallel bus (parallel connection bus 8) form a block (electric cell group 16, 17, 18, or 19), and two or more blocks are connected in series. The two or more cells are connected in series to a fuse (fuse part 10b).
Non-Patent Literature 1 mentions a desirable range of the number of series-connected cells (electric cells). According to Non-Patent Literature 1, the number of series-connected cells is desirably in the range of 5 to 10 because a high charging current (overcharging follow current) will flow to a short-circuited cell when only a small number of cells are connected in series.